The Journal of Medicinal Chemistry, 23, 1358 (1980) discloses certain substituted quinoline-3-carboxylic acids having the structural formula. ##STR1## See also U.S. Pat. No. 4,146,719.
European Patent Publication No. 78362 describes 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-piperazinoquinoline-3-carboxyli c acids.
Certain 7-heterocyclic substituted 1,8-naphthyridines are disclosed in Eur. J. Med. Chem.-Chimica Therapeutica, 29, 27 (1977).
The above references teach that these compounds possess antibacterial activity.